Hydro Toys Combining fun with refreshment, the Hydro Toys are the ultimate chew toys for any hot day. The molded rubber has a foam core, which absorbs and holds liquid. It soaks in water and then releases it through the specially designed holes as its squeezed. They are the perfect way to quench your dogs thirst and play at the same time! 8.5 x 5.4 x 1 Hydro Ring